1. Field of the Invention
This invention principally relates to work-holding apparatus and methods and, more particularly, to an apparatus and method for holding a workpiece having an internal bore so that the surface of the bore can be honed or otherwise machined.
2. Description of the Related Art
Conventional lathe chucks are not well adapted for holding a large object having an internal bore which requires honing, polishing, or various types of machining. Besides the very large size of a chuck needed to hold even a moderately sized cylindrical shell, for example, the jaws of the chuck bear down on just a few points of the workpiece, which tend to deform the shell. Large workpieces are commonly held by hand in order to perform honing operations on the interior surface of a bore in the workpiece. The lack of stability and the development of operator fatigue in such an approach are obvious, and the chance of marring the surface being worked on or of otherwise producing an unsatisfactory result clearly exists. In addition, holding a workpiece by hand against rotating machinery is an inherently risky procedure from the standpoint of operator safety.
It would be a great boon in machine shop practice if there existed a means for holding a workpiece for honing or otherwise machining the inside of a bore in the object without damaging the outer surface of the object, while providing sufficient holding strength and stability. Such a work-holding apparatus would be even more valuable if it were convenient to use, easy to install in a working position, economical to manufacture, and simple to service. It would also be advantageous if such a work-holding means had the capability of gripping a deformable object over its entire outer circumference without distorting its shape because of contact forces concentrated at just a few points.